How broadly exploitable is this vulnerability?

The issue is exploitable in any deployment where attackers can register or obtain accounts that allow file uploads, and where they can convince other users to open links to their uploaded assets. Because the attack executes under the application's origin, the impact can be significant for affected users.

Does an attacker need special privileges to exploit this?

No special administrative privileges are required beyond the ability to upload note assets. Any authenticated user with upload capability can prepare a malicious HTML or SVG asset and then distribute the corresponding URL to potential victims.

What is the safest general fix pattern?

The safest pattern is to ensure that user-uploaded files cannot execute as active content from the application origin. This typically involves serving uploads with explicit, non-executable MIME types, using `Content-Disposition: attachment` for unsafe types, setting `X-Content-Type-Options: nosniff`, and optionally isolating uploads on a separate domain.

Severity:

HIGH RISK

(8.7)

Stored XSS via Unsafe File Handling (CWE-79) in Note Mark Asset Delivery

CVE-2026-40262

Published:

Apr 16, 2026

Status:

Deferred

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

NDV

Recent Vulnerabilities

CWE-74;CWE-89

HIGH RISK

HIGH

(7.3)

SQL Injection via Unsanitized ID Parameter (CWE-89) in Pharmacy Sales and Inventory System /ajax.php

Database Compromise and Data Integrity Loss

April 27, 2026

CWE-863

HIGH RISK

HIGH

(8.5)

Incorrect Authorization (CWE-863) in OpenClaw chat.send Session Management

Privilege Escalation and Unauthorized Session Control

April 27, 2026

Vulnerability Type

Category:

Stored Cross-Site Scripting (XSS) via File Upload

CWE:

CWE-79;CWE-434

Impact:

Authenticated Session Hijacking and Stored Cross-Site Scripting

Severity:

HIGH RISK

(8.7)

CVSS Version:

3.1

Vulnerability Type

Category:

Stored Cross-Site Scripting (XSS) via File Upload

CWE:

CWE-79;CWE-434

Impact:

Authenticated Session Hijacking and Stored Cross-Site Scripting

Severity:

HIGH RISK

(8.7)

CVSS Version:

3.1

Catch This CVE While Code Is Being Written

Detect vulnerable code directly in pull requests, so CVEs are fixed before merge.

Get Started

Ship clean & secure code faster

START 14 DAYS FREE TRIAL

BOOK A DEMO

Made with Love in San Francisco

355 Bryant St. San Francisco, CA 94107, USA

Ask AI for summary of CodeAnt

Made with Love in San Francisco

355 Bryant St. San Francisco, CA 94107, USA

Ask AI for summary of CodeAnt

Made with Love in San Francisco

355 Bryant St. San Francisco, CA 94107, USA

Ask AI for summary of CodeAnt

Stored XSS via Unsafe File Handling (CWE-79) in Note Mark Asset Delivery

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

Recent Vulnerabilities

HIGH RISK

HIGH

(7.3)

SQL Injection via Unsanitized ID Parameter (CWE-89) in Pharmacy Sales and Inventory System /ajax.php

HIGH RISK

HIGH

(8.5)

Incorrect Authorization (CWE-863) in OpenClaw chat.send Session Management

Vulnerability Type

Vulnerability Type

Vulnerability Type

Catch This CVE While Code Is Being Written

Ship clean & secure code faster

Product

Pricing

Company

Legal

Developers

Compare

Product

Pricing

Company

Legal

Developers

Compare

Product

Pricing

Company

Legal

Developers

Compare